PeachParts Mercedes-Benz Forum - View Single Post - New to me '83 240d- flood car, hasn't been started or moved in 14 years

jay_bob · #10 01-15-2018, 01:15 PM

Note OP has an 83 240 D which is the parallel wired system. His relay got shorted out by the flood waters. If he replaces the relay he ought to be just fine.

Good point about the primer pump. Note that the original, white knob, primer pump unscrews to unlock the plunger to pump it up. This pump is notorious for leaking and you may have to replace it, since you will end up just pumping more air into the system if it’s leaking. There is a Bosch replacement for that pump, that is just a big black rubber cylinder that screws into the same hole. This one you just press down on the rubber cylinder to pump the primer. In either case there is a distinct difference in sound once the injection pump is primed. What it is actually doing is forcing extra fuel through the pump and pushing the air and excess fuel down the return line on the back side of the injection pump back to the fuel tank.

Note that this is separate and distinct from the need to purge the injection lines as I mentioned previously.

For education of the OP, the older engines had series wired glow plugs, and instead of an automatic relay that was triggered by turning the key to II position, you pulled out a large heavy knob (known as the “gorilla knob”) and instead of a standard pilot light, there was an extra element in a cage in the dashboard (known as the “salt shaker”) that glowed red.

The newer system (like in your car) has a big relay that is controlled by turning the key to position II. When the light goes off, the timer has determined that you have glowed long enough (based on an ambient temperature sensor in the relay, later models have a temperature sensor in the head). This is your cue to attempt a start.

Note also the 1983 240D has an EGR valve controller box behind the kick plate in the passenger footwell. I would check this out and make sure it’s not shorted out either.